Composition and methods using same for carbon doped silicon containing films

ABSTRACT

A composition and method for using the composition in the fabrication of an electronic device are disclosed. Compounds, compositions and methods for depositing a low dielectric constant (&lt;4.0) and high oxygen ash resistance silicon-containing film such as, without limitation, a carbon doped silicon oxide, are disclosed.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a Divisional application Ser. No. 16/748,914, filedon Jan. 22, 2020. Application Ser. No. 16/748,914 is a divisional of andclaims the benefit of application Ser. No. 15/654,426, filed on Jul. 19,2017, which claims benefit of Application No. 62/367,260, filed on Jul.27, 2016. The disclosure of Application Nos. 15/654,426 and 62/367,260are hereby incorporated by reference.

The subject matter of this disclosure is related to Patent CooperationTreaty Application No. PCT/US2016/016514, filed on Feb. 4, 2016. Thedisclosure of Application No. PCT/US2016/016514, is hereby incorporatedby reference.

BACKGROUND OF THE INVENTION

Described herein is a composition and method for the fabrication of anelectronic device. More specifically, described herein are compounds,and compositions and methods comprising same, for the deposition of alow dielectric constant (<4.0) and high oxygen ash resistancesilicon-containing film such as, without limitation, a carbon dopedsilicon oxide, a carbon doped silicon nitride, a carbon doped siliconoxynitride.

There is a need in the art to provide a composition and method usingsame for depositing high carbon content (e.g., a carbon content of about10 atomic % or greater as measured by X-ray photoelectron spectroscopy(XPS)) doped silicon-containing films for certain applications withinthe electronics industry.

U.S. Pat. No. 8,575,033 describes methods for deposition of siliconcarbide films on a substrate surface. The methods include the use ofvapor phase carbosilane precursors and may employ plasma enhanced atomiclayer deposition processes.

US Publ. No. 2013/022496 teaches a method of forming a dielectric filmhaving Si—C bonds on a semiconductor substrate by atomic layerdeposition (ALD), includes: (i) adsorbing a precursor on a surface of asubstrate; (ii) reacting the adsorbed precursor and a reactant gas onthe surface; and (iii) repeating steps (i) and (ii) to form a dielectricfilm having at least Si—C bonds on the substrate.

PCT Appl. No. WO14134476A1 describes methods for the deposition of filmscomprising SiCN and SIOCN. Certain methods involve exposing a substratesurface to a first and second precursor, the first precursor having aformula (X_(y)H_(3-y)Si)zCH₄—,(X_(y)H_(3-y)Si)(CH₂)(SiX_(p)H_(2-p))(CH₂)(SiX_(y)H_(3-y)), or(X_(y)H_(3-y)Si)(CH₂)_(n)(SiX_(y)H_(3-y)), wherein X is a halogen, y hasa value of between 1 and 3, and z has a value of between 1 and 3, p hasa value of between 0 and 2, and n has a value between 2 and 5, and thesecond precursor comprising a reducing amine. Certain methods alsocomprise exposure of the substrate surface to an oxygen source toprovide a film comprising carbon doped silicon oxide.

Hirose, Y., Mizuno, K., Mizuno, N., Okubo, S., Okubo, S., Yanagida, K.and Yanagita, K. (2014)) “method of manufacturing semiconductor device,substrate processing apparatus, and recording medium” US Appl. No.2014287596A describes a method of manufacturing a semiconductor deviceincluding forming a thin film containing silicon, oxygen and carbon on asubstrate by performing a cycle a predetermined number of times, thecycle including: supplying a precursor gas containing silicon, carbonand a halogen element and having an Si—C bonding, and a first catalyticgas to the substrate; and supplying an oxidizing gas and a secondcatalytic gas to the substrate.

Hirose, Y., Mizuno, N., Yanagita, K. and Okubo, S. (2014)) “Method ofmanufacturing semiconductor device, substrate processing apparatus, andrecording medium.” U.S. Pat. No. 9,343,290 B describes a method ofmanufacturing a semiconductor device includes forming an oxide film on asubstrate by performing a cycle a predetermined number of times. Thecycle includes supplying a precursor gas to the substrate; and supplyingan ozone gas to the substrate. In the act of supplying the precursorgas, the precursor gas is supplied to the substrate in a state where acatalytic gas is not supplied to the substrate, and in the act ofsupplying the ozone gas, the ozone gas is supplied to the substrate in astate where an amine-based catalytic gas is supplied to the substrate.

U.S. Pat. No. 9,349,586 discloses a thin film having a desirable etchingresistance and a low dielectric constant.

US Publ. No. 2015/0044881 A describes a method to form a film containingcarbon added at a high concentration is formed with highcontrollability. A method of manufacturing a semiconductor deviceincludes forming a film containing silicon, carbon and a predeterminedelement on a substrate by performing a cycle a predetermined number oftimes. The predetermined element is one of nitrogen and oxygen. Thecycle includes supplying a precursor gas containing at least two siliconatoms per one mol., carbon and a halogen element and having a Si—Cbonding to the substrate, and supplying a modifying gas containing thepredetermined element to the substrate.

The reference entitled “Highly Stable Ultrathin Carbosiloxane Films byMolecular Layer Deposition”, Han, Z. et al., Journal of PhysicalChemistry C, 2013, 117, 19967 teaches growing carbosiloxane film using1,2-bis[(dimethylamino)dimethylsilyl]ethane and ozone. Thermal stabilityshows film is stable up to 40° C. with little thickness loss at 60° C.

Liu et al, Jpn. J. Appl. Phys., 1999, Vol. 38, 3482-3486, teaches H₂plasma use on polysilsesquioxane deposited with spin-on technology. TheH₂ plasma provides stable dielectric constant and improves film thermalstability and O₂ ash (plasma) treatment.

Kim et al, Journal of the Korean Physical Society, 2002, Vol. 40, 94,teaches H₂ plasma treatment on PECVD carbon doped silicon oxide filmimproves leakage current density (4-5 orders of magnitude) whiledielectric constant increases from 2.2 to 2.5. The carbon doped siliconoxide film after H₂ plasma has less damage to during oxygen ashingprocess.

Posseme et al, Solid State Phenomena, 2005, Vol. 103-104, 337, teachesdifferent H₂/inert plasma treatment on carbon doped silicon oxide PECVDfilm. The k is not improving after H₂ plasma treatment suggesting nobulk modification.

The disclosure of the previously identified patents, patent applicationsand publications is hereby incorporated by reference.

BRIEF SUMMARY OF THE INVENTION

The composition and method described herein overcome the problems of theprior art by providing a composition or formulation for depositing aconformal silicon-containing film forming having one or more of thefollowing properties: i) an etch rate of at least 0.5 times less thanthermal silicon oxide (e.g., 0.45 Å/s in 1:99 dilute HF) as measured indilute hydrofluoric acid and a carbon content of about 10 atomic weightpercent (at. %) or greater as measured by X-ray photospectrometry (XPS);ii) dielectric constant and wet etch rate in dilute HF (dHF) lesssensitive to damage during oxygen ashing process or exposure to oxygenplasma, Oxygen ash resistance can be quantified by damage thicknessafter O₂ ash is <50 Å measured by dHF dip as well as film dielectricconstant after O₂ ash lower than 4.0; iii) dielectric constant less than4.0; and (iv) chlorine impurity in the resulting films less than 2.0 at.%, preferably less than 1.0 at. %, most preferably less than 0.5 at. %.The desirable properties that can be achieved by the instant inventionare illustrated in greater detail in the Examples below.

In one particular embodiment, the composition described herein may beused in a method to deposit a carbon doped silicon oxide film usingthermal atomic layer deposition (ALD).

In one aspect, the composition for depositing a silicon-containing filmcomprises: (a) at least one linear or cyclic silicon precursor compoundhaving one Si—C—Si or two Si—C—Si linkages listed in Table 1 and 2.

TABLE 1 Silicon precursors having one Si—C—Si linkage

1,1,1,3,3,3-hexachloro-1,3- disilapropane

1,1,1,3,3,3-hexachloro-2-methyl-1,3- disilapropane

1,1,1,3,3,3-hexachloro-2,2-dimethyl-1,3- disilapropane

1,1,1,3,3,3-hexachloro-2-ethyl-1,3- disilapropane

TABLE 2 Silicon precursors having two Si—C—Si linkages

1-chloro-1,3-disilacyclobutane

1,3-dichloro- 1,3-disilacyclobutane

1,1-dichloro- 1,3-disilacyclobutane

1,1,3-trichloro- 1,3-disilacyclobutane

1,1,3,3-tetrachloro- 1,3-disilacyclobutane

1-bromo-1,3-disilacyclobutane

1,3-dibromo- 1,3-disilacyclobutane

1,1-dibromo- 1,3-disilacyclobutane

1,1,3-tribromo- 1,3-disilacyclobutane

1,1,3,3-tetrabromo- 1,3-disilacyclobutane

1,3-dichloro-1,3-dimethyl- 1,3-disilacyclobutane

1,1,1,3,3,5,5,5-octachloro-1,3,5- trisilapentane

1,1,1,5,5,5-hexachloro-3,3-dimethyl- 1,3,5-trisilapentane

1,1,1,5,5,5-hexachloro-1,3,5- trisilapentane

1,3-bromo-1,3-dimethyl- 1,3-disilacyclobutane

1,1,1,3,3,5,5,5-octachloro-1,5-dimethyl- 1,3,5-trisilapentane

1,1,3,5,5,5-pentachloro-1,3,5-trimethyl- 1,3,5-trisilapentane

1,1,5,5-tetraachloro-1,3,5-trisilapentaneand in at least one aspect of the invention, (b) at least one solvent.In certain embodiments of the composition described herein, exemplarysolvents can include, without limitation, ether, tertiary amine, alkylhydrocarbon, aromatic hydrocarbon, siloxanes, tertiary aminoether, andcombinations thereof. In certain embodiments, the difference between theboiling point of the silicon compounds and the boiling point of thesolvent is 40° C. or less, less than about 30° C. and in some cases lessthan about 20° C., preferably less than 1000.

In another aspect, there is provided a method for depositing a filmselected from a carbon-doped silicon oxide film and a carbon-dopedsilicon oxynitride film onto at least a surface of a substratecomprising:

-   -   placing the substrate into a reactor;    -   heating the reactor to one or more temperatures ranging from        about 25° C. to about 550° C.;    -   introducing into the reactor a precursor comprising at least one        compound selected from a silicon precursor listed in Table 1 and        2 and combinations thereof;    -   introducing into the reactor a nitrogen source to react with at        least a portion of the precursor to form a carbon doped silicon        nitride film; and    -   treating the carbon doped silicon nitride film with an oxygen        source at one or more temperatures ranging from about 25° C. to        1000° C. or from about 100° to 400° C. under conditions        sufficient to convert the carbon doped silicon nitride film into        the film. In certain embodiments, the carbon doped silicon oxide        film or the carbon doped silicon oxynitride film has a carbon        content of about 10 atomic weight percent (at. %) or greater as        measured by XPS and an etch rate of at least 0.5 times less than        thermal silicon oxide as measured in dilute hydrofluoric acid.

If desired, the invention further comprises treating the carbon dopedsilicon containing film with hydrogen or hydrogen/inert plasma at 25° C.to 600° C.

One aspect of the invention relates to a composition comprising:

-   -   (a) at least one linear or cyclic silicon precursor compound        having one Si—C—Si or two Si—C—Si linkages selected from the        group consisting of 1,1,1,3,3,3-hexachloro-1,3-disilapropane,        1,1,1,3,3,3-hexachloro-2-methyl-1,3-disilapropane,        1,1,1,3,3,3-hexachloro-2,2-dimethyl-1,3-disilapropane,        1,1,1,3,3,3-hexachloro-2-ethyl-1,3-disilapropane,        1-chloro-1,3-disilacyclobutane, 1-bromo-1,3-disilacyclobutane,        1,3-dichloro-1,3-1,3-disilacyclobutane,        1,3-dibromo-1,3-disilacyclobutane,        1,1,3-trichloro-1,3-disilacyclobutane,        1,1,3-tribromo-1,3-disilacyclobutane,        1,1,3,3-tetrachloro-1,3-disilacyclobutane,        1,1,3,3-tetrabromo-1,3-disilacyclobutane,        1,3-dichloro-1,3-dimethyl-1,3-disilacyclobutane,        1,3-bromo-1,3-dimethyl-1,3-disilacyclobutane,        1,1,1,3,3,5,5,5-octachloro-1,3,5-trisilapentane,        1,1,1,3,3,5,5,5-octachloro-1,3,5-trisilapentane,        1,1,1,3,3,5,5,5-octachloro-1,5-dimethyl-1,3,5-trisilapentane,        1,1,1,5,5,5-hexachloro-3,3-dimethyl-1,3,5-trisilapentane,        1,1,3,5,5,5-pentachloro-1,3,5-trimethyl-1,3,5-trisilapentane,        1,1,1,5,5,5-hexachloro-1,3,5-trisilapentane,        1,1,5,5-tetraachloro-1,3,5-trisilapentane; and;    -   (b) at least one solvent.

Another aspect of the invention relates to a method for forming a carbondoped silicon oxide film having carbon content ranging from 15 at % to30 at. % via a thermal ALD process, the method comprising:

-   -   a) placing one or more substrates comprising a surface feature        into a reactor;    -   b) heating to reactor to one or more temperatures ranging from        ambient temperature to about 550° C. and optionally maintaining        the reactor at a pressure of 100 torr or less;    -   c) introducing into the reactor at least one silicon precursor        having two Si—C—Si linkages selected from the group consisting        of 1-chloro-1,3-disilacyclobutane,        1-bromo-1,3-disilacyclobutane,        1,3-dichloro-1,3-1,3-disilacyclobutane,        1,3-dibromo-1,3-disilacyclobutane,        1,1,3-trichloro-1,3-disilacyclobutane,        1,1,3-tribromo-1,3-disilacyclobutane,        1,1,3,3-tetrachloro-1,3-disilacyclobutane,        1,1,3,3-tetrabromo-1,3-disilacyclobutane,        1,3-dichloro-1,3-dimethyl-1,3-disilacyclobutane,        1,3-bromo-1,3-dimethyl-1,3-disilacyclobutane,        1,1,1,3,3,5,5,5-octachloro-1,3,5-trisilapentane,        1,1,1,3,3,5,5,5-octachloro-1,3,5-trisilapentane,        1,1,1,3,3,5,5,5-octachloro-1,5-dimethyl-1,3,5-trisilapentane,        1,1,1,5,5,5-hexachloro-3,3-dimethyl-1,3,5-trisilapentane,        1,1,3,5,5,5-pentachloro-1,3,5-trimethyl-1,3,5-trisilapentane,        1,1,1,5,5,5-hexachloro-1,3,5-trisilapentane,        1,1,5,5-tetraachloro-1,3,5-trisilapentane;    -   d) purge with an inert gas;    -   e) providing a nitrogen source into the reactor to react with        the surface to form a carbon doped silicon nitride film;    -   f) purge with inert gas to remove reaction by-products    -   g) steps c to f are repeated to provide a desired thickness of        carbon doped silicon nitride;    -   h) treating the resulting carbon doped silicon nitride film with        an oxygen source at one or more temperatures ranging from about        ambient temperature to 1000° C. or from about 100° to 400° C. to        convert the carbon doped silicon nitride film into a carbon        doped silicon oxide film; and    -   i) providing post-deposition exposing the carbon doped silicon        oxide film to a plasma comprising hydrogen.

In one aspect of the invention, the substrate comprises silicon orgermanium doped silicon or boron doped silicon or high k material andsubsequent to depositing the inventive carbon doped silicon oxide film,a film comprising silicon nitride or silicon oxide is deposited.

A further aspect of the invention relates to a film having a k of lessthan about 4, a carbon content of at least about 10 at. %, preferably 15at. % or greater, most preferably 20 at. % or greater based on XPSmeasurement and, in another aspect the inventive film can be formedaccording to any of the inventive methods. Since the carbon content isan important factor for reducing the wet etch rate as well as increasingthe ash resistance, the carbon content for this invention ranges from 10at. % to 40 at. %, preferably 15 at. % to 30 at. %, and most preferably20 at. % to 35 at. % as measured by XPS.

Another aspect of the invention relates to stainless steel containerhousing the inventive compositions.

The embodiments of the invention may be used alone or in variouscombinations with each other.

BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS

FIG. 1 Etching profile comparison for1,1,1,3,3,3-hexachloro-1,3-disilapropane (HCDSP) and1,1,3,3-tetrachloro-1,3-disilacyclobutane (TCDSB) carbon doped siliconoxide film after plasma treatment followed by oxygen ash, demonstratingcarbon doped silicon oxide film from TCDSB provides more ash resistancethan that of HCDSP.

DETAILED DESCRIPTION OF THE INVENTION

Described herein are silicon precursor compounds, and compositions andmethods comprising same, to deposit a carbon doped (e.g., having acarbon content of about 10 at. % or greater as measured by XPS)silicon-containing film via a deposition process such as, withoutlimitation, a thermal atomic layer deposition process. The filmdeposited using the composition and method described herein exhibits anextremely low etch rate such as an etch rate of at least 0.5 times lessthan thermal silicon oxide as measured in dilute hydrofluoric acid(e.g., about 0.20 Å/s or less or about 0.15 Å/s or less in dilute HF(0.5 wt. %), or an etch rate of at least 0.1 times less than thermalsilicon oxide, or an etch rate of at least 0.05 times less than thermalsilicon oxide, or an etch rate of at least 0.01 times less than thermalsilicon oxide while exhibiting variability in other tunable propertiessuch as, without limitation, density, dielectric constant, refractiveindex, and elemental composition.

In certain embodiments, the silicon precursor precursors describedherein, and methods using same, impart one or more of the followingfeatures in the following manner. First, the as-deposited, reactivecarbon-doped silicon nitride film is formed using the silicon precursorprecursors comprising a Si—C—Si linkage, and a nitrogen source. Withoutwishing to be bound by any theory or explanation, it is believed thatthe Si—C—Si linkage from the silicon precursor remains in the resultingas-deposited film and provides a high carbon content of at least 10 at.% or greater as measured by XPS (e.g., about 20 to about 30 at. %, about10 to about 20 at. % and in some cases about 10 to about 15 at. %carbon). Second, when exposing the as-deposited film to an oxygensource, such as water, either intermittently during the depositionprocess, as a post-deposition treatment, or a combination thereof, atleast a portion or all of the nitrogen content in the film is convertedto oxygen to provide a film selected from a carbon-doped silicon oxideor a carbon-doped silicon oxynitride film. The nitrogen in theas-deposited film is released as one or more nitrogen-containingby-products such as ammonia or an amine group.

In this or other embodiments, the final film is porous and has a densityof about 1.7 grams/cubic centimeter (g/cc) or less and an etch rate of0.20 Å/s or less in 0.5 wt. % dilute hydrogen fluoride.

In one aspect, the composition for depositing a silicon-containing filmcomprises: (a) at least one silicon precursor compound having oneSi—C—Si or two Si—C—Si linkages selected from the group consisting of1,1,1,3,3,3-hexachloro-1,3-disilapropane,1,1,1,3,3,3-hexachloro-2-methyl-1,3-disilapropane,1,1,1,3,3,3-hexachloro-2,2-dimethyl-1,3-disilapropane,1,1,1,3,3,3-hexachloro-2-ethyl-1,3-disilapropane,1-chloro-1,3-disilacyclobutane, 1-bromo-1,3-disilacyclobutane,1,3-dichloro-1,3-1,3-disilacyclobutane,1,3-dibromo-1,3-disilacyclobutane,1,1,3-trichloro-1,3-disilacyclobutane,1,1,3-tribromo-1,3-disilacyclobutane,1,1,3,3-tetrachloro-1,3-disilacyclobutane,1,1,3,3-tetrabromo-1,3-disilacyclobutane,1,3-dichloro-1,3-dimethyl-1,3-disilacyclobutane,1,3-bromo-1,3-dimethyl-1,3-disilacyclobutane,1,1,1,3,3,5,5,5-octachloro-1,3,5-trisilapentane,1,1,1,3,3,5,5,5-octachloro-1,3,5-trisilapentane,1,1,1,3,3,5,5,5-octachloro-1,5-dimethyl-1,3,5-trisilapentane,1,1,1,5,5,5-hexachloro-3,3-dimethyl-1,3,5-trisilapentane,1,1,3,5,5,5-pentachloro-1,3,5-trimethyl-1,3,5-trisilapentane,1,1,1,5,5,5-hexachloro-1,3,5-trisilapentane,1,1,5,5-tetraachloro-1,3,5-trisilapentane; and; (b) at least onesolvent. In certain embodiments of the composition described herein,exemplary solvents can include, without limitation, ether, tertiaryamine, alkyl hydrocarbon, aromatic hydrocarbon, tertiary aminoether,siloxanes, and combinations thereof. In certain embodiments, thedifference between the boiling point of the compound having one Si—C—Sior two Si—C—Si linkages and the boiling point of the solvent is 40° C.or less. The wt % of silicon precursor compound in the solvent can varyfrom 1 to 99 wt %, or 10 to 90 wt %, or 20 to 80 wt %, or 30 to 70 wt %,or 40 to 60 wt %, to 50 to 50 wt %. In some embodiments, the compositioncan be delivered via direct liquid injection into a reactor chamber forsilicon-containing film using conventional direct liquid injectionequipment and methods.

In one embodiment of the method described herein, the carbon dopedsilicon oxide film having carbon content ranging from 5 at. % to 20 at.% is deposited using a thermal ALD process and a plasma comprisinghydrogen to improve film properties. In this embodiment, the methodcomprises:

-   -   a. placing one or more substrates comprising a surface feature        into a reactor;    -   b. heating to reactor to one or more temperatures ranging from        ambient temperature to about 550° C. and optionally maintaining        the reactor at a pressure of 100 torr or less;    -   c. introducing into the reactor at least one silicon precursor        having one Si—C—Si linkage selected from the group consisting of        1,1,1,3,3,3-hexachloro-1,3-disilapropane,        1,1,1,3,3,3-hexachloro-2-methyl-1,3-disilapropane,        1,1,1,3,3,3-hexachloro-2,2-dimethyl-1,3-disilapropane,        1,1,1,3,3,3-hexachloro-2-ethyl-1,3-disilapropane;    -   d. purge with an inert gas thereby removing unreacted silicon        precursor and forming a composition comprising the purge gas and        silicon precursor;    -   e. providing a nitrogen source into the reactor to react with        the surface to form a silicon carbonitride films;    -   f. purge with inert gas to remove reaction by-products;    -   g. steps c to f are repeated to provide a desired thickness of        carbon doped silicon nitride;    -   h. providing post-deposition treating the carbon doped silicon        nitride film with an oxygen source at one or more temperatures        ranging from about ambient temperature to 1000° C. or from about        100° to 400° C. to convert the carbon doped silicon nitride film        into a carbon doped silicon oxide film either in situ or in        another chamber; and    -   i. providing post-deposition exposing the carbon doped silicon        oxide film to a plasma comprising hydrogen to improve film        properties to improve at least one of the films' properties;    -   j. optionally post-deposition treating the carbon doped silicon        oxide film with a spike anneal at temperatures from 400° to        1000° C. or a UV light source. In this or other embodiments, the        UV exposure step can be carried out either during film        deposition, or once deposition has been completed.

In one embodiment, the substrate includes at least one feature whereinthe feature comprises a pattern trench with aspect ratio of 1:9, openingof 180 nm.

In an embodiment of the method described herein, the carbon dopedsilicon oxide film having carbon content ranging from 15 at. % to 30 at.% is deposited using a thermal ALD process and a plasma comprisinghydrogen to improve film properties. In this embodiment, the methodcomprises:

-   -   a. placing one or more substrates comprising a surface feature        into a reactor (e.g., into a conventional ALD reactor);    -   b. heating to reactor to one or more temperatures ranging from        ambient temperature to about 550° C. and optionally maintaining        the reactor at a pressure of 100 torr or less;    -   c. introducing into the reactor at least one silicon precursor        having two Si—C—Si linkages selected from the group consisting        of 1-chloro-1,3-disilacyclobutane,        1-bromo-1,3-disilacyclobutane,        1,3-dichloro-1,3-1,3-disilacyclobutane,        1,3-dibromo-1,3-disilacyclobutane,        1,1,3-trichloro-1,3-disilacyclobutane,        1,1,3-tribromo-1,3-disilacyclobutane,        1,1,3,3-tetrachloro-1,3-disilacyclobutane,        1,1,3,3-tetrabromo-1,3-disilacyclobutane,        1,3-dichloro-1,3-dimethyl-1,3-disilacyclobutane,        1,3-bromo-1,3-dimethyl-1,3-disilacyclobutane,        1,1,1,3,3,5,5,5-octachloro-1,3,5-trisilapentane,        1,1,1,3,3,5,5,5-octachloro-1,3,5-trisilapentane,        1,1,1,3,3,5,5,5-octachloro-1,5-dimethyl-1,3,5-trisilapentane,        1,1,1,5,5,5-hexachloro-3,3-dimethyl-1,3,5-trisilapentane,        1,1,3,5,5,5-pentachloro-1,3,5-trimethyl-1,3,5-trisilapentane,        1,1,1,5,5,5-hexachloro-1,3,5-trisilapentane,        1,1,5,5-tetraachloro-1,3,5-trisilapentane;    -   d. purge with an inert gas;    -   e. providing a nitrogen source into the reactor to react with        the surface to form a carbon doped silicon nitride film;    -   f. purge with inert gas to remove reaction by-products;    -   g. steps c to f are repeated to provide a desired thickness of        carbon doped silicon nitride;    -   h. providing post-deposition treating the carbon doped silicon        nitride film with an oxygen source at one or more temperatures        ranging from about ambient temperature to 1000° C. or from about        100° to 400° C. to convert the carbon doped silicon nitride film        into a carbon doped silicon oxide film either in situ or in        another chamber;    -   i. providing post-deposition exposing the carbon doped silicon        oxide film to a plasma comprising hydrogen to improve at least        one of the films' physical properties.    -   j. optionally post-deposition treating the carbon doped silicon        oxide film with a thermal anneal at temperatures from 400° to        1000° C. or a UV light source. In this or other embodiments, the        UV exposure step can be carried out either during film        deposition, or once deposition has been completed.

In yet another further embodiment of the method described herein, thesilicon containing film is deposited using a thermal ALD process with acatalyst comprising an ammonia or organic amine. In this embodiment, themethod comprises:

-   -   a. placing one or more substrates comprising a surface feature        into a reactor;    -   b. heating the reactor to one or more temperatures ranging from        ambient temperature to about 150° C. and optionally maintaining        the reactor at a pressure of 100 torr or less;    -   c. introducing into the reactor at least one silicon precursor        having one or two Si—C—Si linkages selected from the group        consisting of 1,1,1,3,3,3-hexachloro-1,3-disilapropane,        1,1,1,3,3,3-hexachloro-2-methyl-1,3-disilapropane,        1,1,1,3,3,3-hexachloro-2,2-dimethyl-1,3-disilapropane,        1,1,1,3,3,3-hexachloro-2-ethyl-1,3-disilapropane,        1-chloro-1,3-disilacyclobutane, 1-bromo-1,3-disilacyclobutane,        1,3-dichloro-1,3-1,3-disilacyclobutane,        1,3-dibromo-1,3-disilacyclobutane,        1,1,3-trichloro-1,3-disilacyclobutane,        1,1,3-tribromo-1,3-disilacyclobutane,        1,1,3,3-tetrachloro-1,3-disilacyclobutane,        1,1,3,3-tetrabromo-1,3-disilacyclobutane,        1,3-dichloro-1,3-dimethyl-1,3-disilacyclobutane,        1,3-bromo-1,3-dimethyl-1,3-disilacyclobutane,        1,1,1,3,3,5,5,5-octachloro-1,3,5-trisilapentane,        1,1,1,3,3,5,5,5-octachloro-1,3,5-trisilapentane,        1,1,1,3,3,5,5,5-octachloro-1,5-dimethyl-1,3,5-trisilapentane,        1,1,1,5,5,5-hexachloro-3,3-dimethyl-1,3,5-trisilapentane,        1,1,3,5,5,5-pentachloro-1,3,5-trimethyl-1,3,5-trisilapentane,        1,1,1,5,5,5-hexachloro-1,3,5-trisilapentane,        1,1,5,5-tetraachloro-1,3,5-trisilapentane and a catalyst;    -   d. purge with an inert gas    -   e. providing vapors of water into the reactor to react with the        precursor as well as a catalyst to form a carbon doped silicon        oxide as-deposited film;    -   f. purge with inert gas to remove reaction by-products;    -   g. steps c to f are repeated to provide a desired thickness of        carbon doped silicon oxide;    -   h. providing post-deposition exposing the processed film to a        plasma comprising hydrogen to improve film properties to improve        at least one of the films' properties;    -   i. optionally post-deposition treating the carbon doped silicon        oxide film with a spike anneal at temperatures from 400° to        1000° C. or a UV light source. In this or other embodiments, the        UV exposure step can be carried out either during film        deposition, or once deposition has been completed.

In this or other embodiments, the catalyst is selected from a Lewis basesuch as pyridine, piperazine, ammonia, triethylamine or other organicamines. The amount of Lewis base vapors is at least one equivalent tothe amount of the silicon precursor vapors during step c.

In certain embodiments, the resulting carbon doped silicon oxide film isexposed to organoaminosilanes or chlorosilanes having Si-Me or Si—H orboth to form a hydrophobic thin layer before exposing to hydrogen plasmatreatment. Suitable organoaminosilanes include, but not limited to,diethylaminotrimethylsilane, dimethylaminotrimethylsilane,ethylmethylaminotrimethylsilane, t-butylaminotrimethylsilane,iso-propylaminotrimethylsilane, di-isopropylaminotrimethylsilane,pyrrolidinotrimethylsilane, diethylaminodimethylsilane,dimethylaminodimethylsilane, ethylmethylaminodimethylsilane,t-butylaminodimethylsilane, iso-propylaminodimethylsilane,di-isopropylaminodimethylsilane, pyrrolidinodimethylsilane,bis(diethylamino)dimethylsilane, bis(dimethylamino)dimethylsilane,bis(ethylmethylamino)dimethylsilane,bis(di-isopropyllamino)dimethylsilane,bis(iso-propylamino)dimethylsilane, bis(tert-butylamino)dimethylsilane,dipyrrolidinodimethylsilane, bis(diethylamino)diethylsilane,bis(diethylamino)methylvinylsilane, bis(dimethylamino)methylvinylsilanebis(ethylmethylamino)methylvinylsilane,bis(di-isopropyllamino)methylvinylsilane,bis(iso-propylamino)methylvinylsilane,bis(tert-butylamino)methylvinylsilane, dipyrrolidinomethylvinylsilane,2,6-dimethylpiperidinomethylsilane,2,6-dimethylpiperidinodimethylsilane,2,6-dimethylpiperidinotrimethylsilane, tris(dimethylamino)phenylsilane,tris(dimethylamino)methylsilane, di-iso-propylaminosilane,di-sec-butylaminosilane, chlorodimethylsilane, chlorotrimethylsilane,dichloromethylsilane, and dichlorodimethylsilane.

In another embodiments, the resulting carbon doped silicon oxide film isexposed to alkoxysilanes or cyclic alkoxysilanes having Si-Me or Si—H orboth to form a hydrophobic thin layer before exposing to hydrogen plasmatreatment. Suitable alkoxysilanes or cyclic alkoxysilanes include, butnot limited to, diethoxymethylsilane, dimethoxymethylsilane,diethoxydmethylsilane, dimethoxydmethylsilane,2,4,6,8-Tetramethylcyclotetrasiloxane, or octamethylcyclotetrasiloxane.Without wishing to be bound by any theory or explanation, it is believedthat the thin layer formed by the organoaminosilanes or alkoxysilanes orcyclic alkoxysilanes may convert into dense carbon doped silicon oxideduring plasma ashing process, further boosting the ashing resistance.

In another embodiment, a vessel for depositing a silicon-containing filmcomprising one or more silicon precursor compounds described herein. Inone particular embodiment, the vessel comprises at least onepressurizable vessel (preferably of stainless steel having a design suchas disclosed in U.S. Pat. Nos. 7,334,595; 6,077,356; 5,069,244; and5,465,766 the disclosure of which is hereby incorporated by reference.The container can comprise either glass (borosilicate or quartz glass)or type 316, 316L, 304 or 304L stainless steel alloys (UNS designationS31600, S31603, S30400 S30403) fitted with the proper valves andfittings to allow the delivery of one or more precursors to the reactorfor a CVD or an ALD process. In this or other embodiments, the siliconprecursor is provided in a pressurizable vessel comprised of stainlesssteel and the purity of the precursor is 98% by weight or greater or99.5% or greater which is suitable for the semiconductor applications.The silicon precursor compounds are preferably substantially free ofmetal ions such as, Al³⁺ ions, Fe²⁺, Fe³⁺, Ni²⁺, Cr³⁺. As used herein,the term “substantially free” as it relates to Al³⁺ ions, Fe²⁺, Fe³⁺,Ni²⁺, Cr³⁺ means less than about 5 ppm (by weight), preferably less thanabout 3 ppm, and more preferably less than about 1 ppm, and mostpreferably about 0.1 ppm. In certain embodiments, such vessels can alsohave means for mixing the precursors with one or more additionalprecursor if desired. In these or other embodiments, the contents of thevessel(s) can be premixed with an additional precursor. Alternatively,the silicon precursor is and/or other precursor can be maintained inseparate vessels or in a single vessel having separation means formaintaining the silicon precursor is and other precursor separate duringstorage.

The silicon-containing film is deposited upon at least a surface of asubstrate such as a semiconductor substrate. In the method describedherein, the substrate may be comprised of and/or coated with a varietyof materials well known in the art including films of silicon such ascrystalline silicon or amorphous silicon, silicon oxide, siliconnitride, amorphous carbon, silicon oxycarbide, silicon oxynitride,silicon carbide, germanium, germanium doped silicon, boron dopedsilicon, metal such as copper, tungsten, aluminum, cobalt, nickel,tantalum), metal nitride such as titanium nitride, tantalum nitride,metal oxide, group Ill/V metals or metalloids such as GaAs, InP, GaP andGaN, and a combination thereof. These coatings may completely coat thesemi-conductor substrate, may be in multiple layers of various materialsand may be partially etched to expose underlying layers of material. Thesurface may also have on it a photoresist material that has been exposedwith a pattern and developed to partially coat the substrate. In certainembodiments, the semiconductor substrate comprising at least one surfacefeature selected from the group consisting of pores, vias, trenches, andcombinations thereof. The potential application of thesilicon-containing films include but not limited to low k spacer forFinFET or nanosheet, sacrificial hard mask for self aligned patterningprocess (such as SADP, SAQP, or SAOP).

The deposition method used to form the silicon-containing films orcoatings are deposition processes. Examples of suitable depositionprocesses for the method disclosed herein include, but are not limitedto, a chemical vapor deposition or an atomic layer deposition process.As used herein, the term “chemical vapor deposition processes” refers toany process wherein a substrate is exposed to one or more volatileprecursors, which react and/or decompose on the substrate surface toproduce the desired deposition. As used herein, the term “atomic layerdeposition process” refers to a self-limiting (e.g., the amount of filmmaterial deposited in each reaction cycle is constant), sequentialsurface chemistry that deposits films of materials onto substrates ofvarying compositions. As used herein, the term “thermal atomic layerdeposition process” refers to atomic layer deposition process atsubstrate temperatures ranging from room temperature to 600° C. withoutin situ or remote plasma. Although the precursors, reagents and sourcesused herein may be sometimes described as “gaseous”, it is understoodthat the precursors can be either liquid or solid which are transportedwith or without an inert gas into the reactor via direct vaporization,bubbling or sublimation. In some case, the vaporized precursors can passthrough a plasma generator.

In one embodiment, the silicon-containing film is deposited using an ALDprocess. In another embodiment, the silicon-containing film is depositedusing a CCVD process. In a further embodiment, the silicon-containingfilm is deposited using a thermal ALD process. The term “reactor” asused herein, includes without limitation, reaction chamber or depositionchamber.

In certain embodiments, the method disclosed herein avoids pre-reactionof precursor(s) by using ALD or CCVD methods that separate theprecursor(s) prior to and/or during the introduction to the reactor. Inthis connection, deposition techniques such as ALD or CCVD processes areused to deposit the silicon-containing film. In one embodiment, the filmis deposited via an ALD process in a typical single wafer ALD reactor,semi-batch ALD reactor, or batch furnace ALD reactor by exposing thesubstrate surface alternatively to the one or more thesilicon-containing precursor, oxygen source, nitrogen-containing source,or other precursor or reagent. Film growth proceeds by self-limitingcontrol of surface reaction, the pulse length of each precursor orreagent, and the deposition temperature. However, once the surface ofthe substrate is saturated, the film growth ceases. In anotherembodiment, each reactant including the silicon precursor and reactivegas is exposed to a substrate by moving or rotating the substrate todifferent sections of the reactor and each section is separated by inertgas curtain, i.e. spatial ALD reactor or roll to roll ALD reactor.

Depending upon the deposition method, in certain embodiments, thesilicon precursors described herein and optionally othersilicon-containing precursors may be introduced into the reactor at apredetermined molar volume, or from about 0.1 to about 1000 micromoles.In this or other embodiments, the precursor may be introduced into thereactor for a predetermined time period. In certain embodiments, thetime period ranges from about 0.001 to about 500 seconds.

In certain embodiments, the silicon-containing films deposited using themethods described herein are formed in the presence of a catalyst incombination with an oxygen source, reagent or precursor comprisingoxygen, i.e. water vapors. An oxygen source may be introduced into thereactor in the form of at least one oxygen source and/or may be presentincidentally in the other precursors used in the deposition process.Suitable oxygen source gases may include, for example, water (H2O)(e.g., deionized water, purified water, distilled water, water vapor,water vapor plasma, oxygenated water, air, a composition comprisingwater and other organic liquid), oxygen (O2), oxygen plasma, ozone (O3),nitric oxide (NO), nitrogen dioxide (NO2), carbon monoxide (CO), aplasma comprising water, a plasma comprising water and argon, hydrogenperoxide, a composition comprising hydrogen, a composition comprisinghydrogen and oxygen, carbon dioxide (CO2), air, and combinationsthereof. In certain embodiments, the oxygen source comprises an oxygensource gas that is introduced into the reactor at a flow rate rangingfrom about 1 to about 10000 square cubic centimeters (sccm) or fromabout 1 to about 1000 sccm. The oxygen source can be introduced for atime that ranges from about 0.1 to about 100 seconds. The catalyst isselected from a Lewis base such as pyridine, piperazine, trimethylamine,tert-butylamine, diethylamine, trimethylamine, ethylenediamine, ammonia,or other organic amines.

In embodiments wherein the film is deposited by an ALD or a cyclic CVDprocess, the precursor pulse can have a pulse duration that is greaterthan 0.01 seconds, and the oxygen source can have a pulse duration thatis less than 0.01 seconds, while the water pulse duration can have apulse duration that is less than 0.01 seconds.

In certain embodiments, the oxygen source is continuously flowing intothe reactor while precursor pulse and plasma are introduced in sequence.The precursor pulse can have a pulse duration greater than 0.01 secondswhile the plasma duration can range between 0.01 seconds to 100 seconds.

In certain embodiments, the silicon-containing films comprise siliconand nitrogen. In these embodiments, the silicon-containing filmsdeposited using the methods described herein are formed in the presenceof nitrogen-containing source. A nitrogen-containing source may beintroduced into the reactor in the form of at least one nitrogen sourceand/or may be present incidentally in the other precursors used in thedeposition process.

Suitable nitrogen-containing or nitrogen source gases may include, forexample, ammonia, hydrazine, monoalkylhydrazine, symmetrical orunsymmetrical dialkylhydrazine, organoamines such as methylamine,ethylamine, ethylenediamine, ethanolamine, piperazine,N,N′-dimethylethylenediamine, imidazolidine, cyclotrimethylenetriamine,and combination thereof.

In certain embodiments, the nitrogen source is introduced into thereactor at a flow rate ranging from about 1 to about 10000 square cubiccentimeters (sccm) or from about 1 to about 1000 sccm. Thenitrogen-containing source can be introduced for a time that ranges fromabout 0.1 to about 100 seconds. In embodiments wherein the film isdeposited by an ALD or a cyclic CVD process using both a nitrogen andoxygen source, the precursor pulse can have a pulse duration that isgreater than 0.01 seconds, and the nitrogen source can have a pulseduration that is less than 0.01 seconds, while the water pulse durationcan have a pulse duration that is less than 0.01 seconds. In yet anotherembodiment, the purge duration between the pulses that can be as low as0 seconds or is continuously pulsed without a purge in-between.

The deposition methods disclosed herein may involve one or more purgegases. The purge gas, which is used to purge away unconsumed reactantsand/or reaction byproducts, is an inert gas that does not react with theprecursors. Exemplary purge gases include, but are not limited to, argon(Ar), nitrogen (N₂), helium (He), neon, hydrogen (H₂), and combinationsthereof. In certain embodiments, a purge gas such as Ar is supplied intothe reactor at a flow rate ranging from about 10 to about 10000 sccm forabout 0.1 to 1000 seconds, thereby purging the unreacted material andany byproduct that may remain in the reactor.

The respective step of supplying the precursors, oxygen source, thenitrogen-containing source, and/or other precursors, source gases,and/or reagents may be performed by changing the time for supplying themto change the stoichiometric composition of the resulting film.

Energy is applied to the at least one of the precursor,nitrogen-containing source, reducing agent, other precursors orcombination thereof to induce reaction and to form the film or coatingon the substrate. Such energy can be provided by, but not limited to,thermal, plasma, pulsed plasma, helicon plasma, high density plasma,inductively coupled plasma, X-ray, e-beam, photon, remote plasmamethods, and combinations thereof.

In certain embodiments, a secondary RF frequency source can be used tomodify the plasma characteristics at the substrate surface. Inembodiments wherein the deposition involves plasma, the plasma-generatedprocess may comprise a direct plasma-generated process in which plasmais directly generated in the reactor, or alternatively a remoteplasma-generated process in which plasma is generated outside of thereactor and supplied into the reactor.

Throughout the description, the term “ALD or ALD-like” refers to aprocess including, but not limited to, the following processes: a) eachreactant including silicon precursor and reactive gas is introducedsequentially into a reactor such as a single wafer ALD reactor,semi-batch ALD reactor, or batch furnace ALD reactor; b) each reactantincluding silicon precursor and reactive gas is exposed to a substrateby moving or rotating the substrate to different sections of the reactorand each section is separated by inert gas curtain, i.e. spatial ALDreactor or roll to roll ALD reactor.

The silicon precursors and/or other silicon-containing precursors may bedelivered to the reaction chamber, such as a CVD or ALD reactor, in avariety of ways. In one embodiment, a liquid delivery system may beutilized. In an alternative embodiment, a combined liquid delivery andflash vaporization process unit may be employed, such as, for example,the turbo vaporizer manufactured by MSP Corporation of Shoreview, Minn.,to enable low volatility materials to be volumetrically delivered, whichleads to reproducible transport and deposition without thermaldecomposition of the precursor. In liquid delivery formulations, theprecursors described herein may be delivered in neat liquid form, oralternatively, may be employed in solvent formulations or compositionscomprising same. Thus, in certain embodiments the precursor formulationsmay include solvent component(s) of suitable character as may bedesirable and advantageous in a given end use application to form a filmon a substrate.

In this or other embodiments, it is understood that the steps of themethods described herein may be performed in a variety of orders, may beperformed sequentially or concurrently (e.g., during at least a portionof another step), and any combination thereof. The respective step ofsupplying the precursors and the nitrogen-containing source gases may beperformed by varying the duration of the time for supplying them tochange the stoichiometric composition of the resultingsilicon-containing film.

In a still further embodiment of the method described herein, the filmor the as-deposited film is subjected to a treatment step. The treatmentstep can be conducted during at least a portion of the deposition step,after the deposition step, and combinations thereof. Exemplary treatmentsteps include, without limitation, treatment via high temperaturethermal annealing; plasma treatment; ultraviolet (UV) light treatment;laser; electron beam treatment and combinations thereof to affect one ormore properties of the film. The films deposited with the siliconprecursors having one or two Si—C—Si linkages described herein, whencompared to films deposited with previously disclosed silicon precursorsunder the same conditions, have improved properties such as, withoutlimitation, a wet etch rate that is lower than the wet etch rate of thefilm before the treatment step or a density that is higher than thedensity prior to the treatment step. In one particular embodiment,during the deposition process, as-deposited films are intermittentlytreated. These intermittent or mid-deposition treatments can beperformed, for example, after each ALD cycle, after a certain number ofALD, such as, without limitation, one (1) ALD cycle, two (2) ALD cycles,five (5) ALD cycles, or after every ten (10) or more ALD cycles.

In an embodiment wherein the film is treated with a high temperatureannealing step, the annealing temperature is at least 100° C. or greaterthan the deposition temperature. In this or other embodiments, theannealing temperature ranges from about 400° C. to about 1000° C. Inthis or other embodiments, the annealing treatment can be conducted in avacuum (<760 Torr), inert environment or in oxygen containingenvironment (such as H₂O, N₂O, NO₂ or O₂)

In an embodiment wherein the film is treated to UV treatment, film isexposed to broad band UV or, alternatively, an UV source having awavelength ranging from about 150 nanometers (nm) to about 400 nm. Inone particular embodiment, the as-deposited film is exposed to UV in adifferent chamber than the deposition chamber after a desired filmthickness is reached.

In an embodiment where in the film is treated with a plasma, passivationlayer such as SiO₂ or carbon doped SiO₂ is deposited to prevent chlorineand nitrogen contamination from penetrating film in the subsequentplasma treatment. The passivation layer can be deposited using atomiclayer deposition or cyclic chemical vapor deposition.

In an embodiment wherein the film is treated with a plasma, the plasmasource is selected from the group consisting of hydrogen plasma, plasmacomprising hydrogen and helium, plasma comprising hydrogen and argon.Hydrogen plasma lowers film dielectric constant and boost the damageresistance to following plasma ashing process while still keeping thecarbon content in the bulk almost unchanged.

Throughout the description, the term “ALD or ALD-like” refers to aprocess including, but not limited to, the following processes: a) eachreactant including silicon precursor and reactive gas is introducedsequentially into a reactor such as a single wafer ALD reactor,semi-batch ALD reactor, or batch furnace ALD reactor; b) each reactantincluding silicon precursor and reactive gas is exposed to a substrateby moving or rotating the substrate to different sections of the reactorand each section is separated by inert gas curtain, i.e. spatial ALDreactor or roll to roll ALD reactor.

Throughout the description, the term “ashing” refers to a process toremove the photoresist or carbon hard mask in semiconductormanufacturing process using a plasma comprising oxygen source such asO₂/inert gas plasma, O₂ plasma, CO₂ plasma, CO plasma, H₂/O₂ plasma orcombination thereof.

Throughout the description, the term “damage resistance” refers to filmproperties after oxygen ashing process. Good or high damage resistanceis defined as the following film properties after oxygen ashing: filmdielectric constant lower than 4.5; carbon content in the bulk (at morethan 50 Å deep into film) is within 5 at. % as before ashing; Less than50 Å of the film is damaged, observed by differences in dilute HF etchrate between films near surface (less than 50 Å deep) and bulk (morethan 50 Å deep).

Throughout the description, the term “alkyl hydrocarbon” refers a linearor branched C₁ to C₂₀ hydrocarbon, cyclic C₆ to C₂₀ hydrocarbon.Exemplary hydrocarbon includes, but not limited to, heptane, octane,nonane, decane, dodecane, cyclooctane, cyclononane, cyclodecane.

Throughout the description, the term “aromatic hydrocarbon” refers a C₆to C₂₀ aromatic hydrocarbon. Exemplary aromatic hydrocarbon n includes,but not limited to, toluene, mesitylene.

Throughout the description, the term “catalyst” refers a Lewis base invapor phase which can catalyze surface reaction between hydroxyl groupand Si—Cl bond during thermal ALD process. Exemplary catalysts include,but not limited to, at least one of a cyclic amine-based gas such asaminopyridine, picoline, lutidine, piperazine, piperidine, pyridine oran organic amine-based gas methylamine, dimethylamine, trimethylamine,ethylamine, diethylamine, triethylamine, propylamine, iso-propylamine,di-propylamine, di-iso-propylamine, tert-butylamine.

Throughout the description, the term “organic amines” refers a primaryamine, secondary amine, tertiary amine having C₁ to C₂₀ hydrocarbon,cyclic C₆ to C₂₀ hydrocarbon. Exemplary organic amines include, but notlimited to, methylamine, dimethylamine, trimethylamine, ethylamine,diethylamine, triethylamine, propylamine, iso-propylamine,di-propylamine, di-iso-propylamine, tert-butylamine.

Throughout the description, the term “siloxanes” refer a linear,branched, or cyclic liquid compound having at least one Si—O—Si linkagesand C₄ to C₂₀ carbon atoms. Exemplary siloxanes includes, but notlimited to, tetramethyldisiloxane, hexamethyldisiloxane (HMDSO),1,1,1,3,3,5,5,5-octamethyltrisiloxane, octamethylcyclotetrasiloxane(OMCTS).

Throughout the description, the term “step coverage” as used herein isdefined as a percentage of two thicknesses of the deposited film in astructured or featured substrate having either vias or trenches or both,with bottom step coverage being the ratio (in %): thickness at thebottom of the feature is divided by thickness at the top of the feature,and middle step coverage being the ratio (in %): thickness on a sidewallof the feature is divided by thickness at the top of the feature. Filmsdeposited using the method described herein exhibit a step coverage ofabout 80% or greater, or about 90% or greater which indicates that thefilms are conformal.

The following examples illustrate certain aspects of the instantinvention and do not limit the scope of the appended claims.

EXAMPLES General Film Deposition

Film depositions were performed in a lab scale atomic layer deposition(ALD) reactor using a silicon precursor and ammonia as nitrogen sourceammonia. The ALD cycle steps and process conditions are provided in thefollowing Table 3:

TABLE 3 ALD Cycle Steps and Process Conditions Steps Descriptions TimeNotes  1 Insert Si substrates into a reactor  2 Heat substrates todesired ~1-2 hours T = 300-500° C. temperature  3 Close throttle valve 2 Throttle valve is seconds (s) closed to increase residence time  4Deliver silicon precursor  2 s Vapor draw; vapor dose pressure is 14-18Torr  5 Deliver silicon precursor  2 s dose  6 Deliver silicon precursor 2 s After 3 doses of Si dose precursor,  7 Open throttle valve  2 s  8Flow N₂ to purge the reactor  6 s N₂ flow is 5 Ipm  9 Evacuate thereactor to base  6 s Base pressure is pressure <1 mTorr 10 Flow NH₃ 24 sPressure is set to 5 Torr; NH₃ flow is 100 sccm  9 Flow N₂ to purge thereactor  6 s N₂ flow is 5 Ipm 10 Evacuate the reactor to base  6 s Basepressure is pressure <1 mTorr 11 Remove Si sample from the reactor

During the deposition, steps 3 to 10 are repeated for a number of cyclesof up to 2000 times to get a desired thickness of the as-depositedcarbon doped silicon nitride films.

The resulting as-deposited films were subjected to either an in-situ(annealing performed inside the reactor on the as-deposited film) orex-situ annealing (annealing outside or in a separate chamber) toconvert into the films into a carbon doped silicon oxide films. Typicalannealing conditions performed were as follows: moisture annealing wasperformed under vacuum at 30 Torr; air annealing was performed on a hotplate at ambient temperature (e.g., 25° C.) or about 300° C.

Standard hydrogen containing plasma were used to treat a carbon dopedsilicon oxide film. The H₂ plasma treatment parameters are:

-   -   a. H₂ only plasma:        -   Plasma frequency=13.56 MHz        -   H₂ flow=135 sccm        -   Chamber pressure=2 Torr        -   Time=5 minutes    -   b. H₂/Ar plasma        -   Plasma frequency=13.56 MHz        -   H₂ flow=65 sccm        -   Ar flow=65 sccm        -   Chamber pressure=2 Torr        -   Time=5 minutes

Refractive index and thickness were measured directly after depositionusing an ellipsometer at 632.8 nm. Bulk film composition wascharacterized using X-Ray Photoelectron Spectroscopy (XPS) at fewnanometer (2-5 nm) down from the surface inorder to eliminate effect ofadventitious carbon. Film density was characterized using X-RayReflectometry (XRR).

Wet etch rate process was performed under two different concentration ofdilute hydrofluoric acid (dHF), 1:199 49% HF and DI water as well as1:99 49% HF and DI water). The more dilute HF concentration increasesmeasurement accuracy for damaged layer. During the process, a thermalsilicon oxide film was etched at the same time used to ensure etchsolution consistency.

Oxygen ashing process was performed at room temperature using commercialplasma asher PVA TePLA M4L. The process parameters are as follow:power=100−200 W; He/O₂=1:3; pressure=600 mTorr. Film dielectric constant(k) is calculated from C-V curve measured using MDC 802b Mercury Probeconnected to HP4284 LCR meter. Measurement was done in a front-contactmode, which liquid metal (mercury) was used to form two electricallyconductive contacts.

Example 1: Low Dielectric Constant and High Oxygen Ash Resistance ofCarbon Doped Silicon Oxide Film Via Thermal ALD Deposition

Carbon doped silicon oxide film was deposited using thermal ALD processusing 1,1,3,3-tetrachlorodisilacyclobutane (TCDSB) and1,1,1,3,3,3-hexachloro-1,3-disilapropane (HCDSP) and ammonia at 300° C.as described in Table 3.

After deposition the film was then further treated ex-situ for 3 hoursat 300° C. in air.

TABLE 4 Film composition for carbon doped silicon oxide film depositedfrom 1,1,3,3-tetrachloro-1,3-disilcyclobutane and ammonia followed byannealing measured by XPS Si precursor C N O Si Cl1,1,1,3,3,3-hexachloro-  9.5% 1.1% 56.8% 32.6% ND 1,3-disilapropane(HCDSP) 1,1,3,3- 27.5% 1.2% 39.2% 40.3% ND tetrachlorodisilacyclobu-tane (TCDSB)

Table 4. shows film composition comparison between film deposited fromHCDSP and TCDSB. The TCDSB film has a relatively large carbon contentcompared to HCDSP, demonstrating TCDSM is a better silicon precursor tointroduce more carbon than HCDSP.

The dHF etch rate for thermal silicon oxide reference etch rate is0.48±0.02 Å/s. the etch rate for HCDSP and TCDSB films are 0.10 Å/s and<0.02 Å/s consecutively.

The TDCSB film etch rate is below detection, limit of our measurement.Lower TDCSB film dilute HF etch rate (>5× lower) is consistent withhigher carbon content in the film.

Film dielectric constant for either carbon doped silicon oxide filmdeposited from HCDSP or TCDSB are greater than 5.

The resulted carbon doped silicon oxide film deposited from HCDSP orTCDSB films were further treated with hydrogen plasma using 300 mmcommercial PEALD tool using H₂/Ar plasma using the conditions asaforementioned. Both HCDSP and TCDSB film have dielectric constantreduced to 3.5 and 3.4 respectively after plasma treatment,demonstrating plasma comprising hydrogen is an effective way to reducedielectric constant.

The films were then exposed to standard oxygen ash followed by dilute HFdip to determine damage. Referring now to FIG. 1, FIG. 1 shows filmthickness removed as function of time when dipping in dilute HF.

Both HCDSP and TCDSB films shows fast etch rate in the beginning beforeslowing down, indicating surface damage from oxygen ash. Oxygen ashoxidizes carbon from the film, hence, causing fast etch rate. Etch rateprofile suggests damaged layer of 27 Å for TCDSB film and 39 Å for HCDSPfilm, suggesting TCDSB film is more oxygen ash resistance than HCDSPfilm under the same etching conditions.

Example 2. Step Coverage of Carbon Doped Silicon Oxide Film from1,1,3,3-tetrachloro-1,3-disilacyclobutane

Carbon doped silicon oxide film on pattern structure was deposited from1,1,3,3-tetrachloro-1,3-disilacyclobutane and ammonia at 300° C. asdescribed in Table 3 followed by ex-situ treatment to 300° C. for 3hours in air environment.

Scanning electron microscope (SEM) was performed on the trench structurewith aspect ratio of 1:9 and trench opening of 180 nm.

TABLE 5 Surface coverage of carbon doped silicon oxide film depositedfrom 1,1,3,3-tetrachloro-1,3-disilacyclobutane 1/4 from 3/4 from Top topMiddle top Bottom Thickness 456 Å 476 Å 473 Å 456 Å 476 Å (Å)

The step coverage, shown in Table 5, for carbon doped silicon oxide filmdeposited from 1,1,3,3-tetrachloro-1,3-disilacyclobutane is >99%.

Example 3. Deposition of Silicon-Containing Film Via Thermal ALDDeposition Using 1,1,3,3-tetrachloro-1,3-disilacyclobutane

Silicon-containing films were deposited from1,1,3,3-tetrachloro-1,3-disilacyclobutane and ammonia at substratetemperature of 500° C. using the process steps described in Table 3 andstored in ambient.

Film properties such as XPS and wet etch rate in dilute HF were obtainedapproximately a week after film deposition. The results of these testsare provided in Table 6.

TABLE 6 Film composition and WER of ALD films dHF WER relative toTemperature (° C.) % O % N % C % Cl % Si thermal oxide 500 20.1 18.123.9 0.4 37.6 0.12

Referring to Table 6, the XPS data shows that the carbon doped siliconoxide had little chlorine content (e.g., less than 0.5 at. %). The filmdeposited at 500° C. is has more nitrogen content compared to 300° C.while maintaining similar amount of carbon in the film. It is believedthat at the lower deposition temperature of 300° C., the process mayprovide more Si—NH₂ or Si—NH—Si fragments that are susceptible tooxidation. Deposition at the higher 500° C. temperature, on the otherhand, may provide enough energy to form a stronger Si—N_(x) networkwhich is more resistant to oxidation.

Example 4. In-Situ Annealing of Carbon Doped Silicon Oxide FilmDeposited from 1,1,3,3-tetrachloro-1,3-disilacyclobutane

Carbon doped silicon oxide film was deposited using1,1,3,3-tetrachloro-1,3-disilacyclobutane and ammonia at 300° C. asdescribed in Table 3. In-situ H₂O vapor treatment was performed on thefilm using the following parameters:

H₂O vapor draw; H₂O canister temperature=50° C.; Chamber pressure=30Torr; T=300° C.

Film growth per cycle was 0.48 Å/cycle. The resulting film hasrefractive index of 1.55 and density of 1.55 g/cc. The film compositionmeasured by XPS is O=39.0%, N=2.6%, C=25.1% and Si=33.2%. No chlorinedetected in the film.

Example 5. Oxygen Ash Resistance of Carbon Doped Silicon Oxide FilmDeposited Via Thermal ALD Deposition Using1,1,3,3-tetrachloro-1,3-disilacyclobutane and Ammonia Followed byThermal Annealing and Plasma Treatment

Carbon doped silicon oxide film was deposited using1,1,3,3-tetrachloro-1,3-disilacyclobutane and ammonia at 300° C. asdescribed in Table 3 followed by thermal treatment at 300° C. in air.The carbon doped silicon oxide film was further heated in nitrogen at200-400° C., 5 Torr, for 1 hour prior to H₂/Ar plasma treatmentdescribed previously.

The film was then exposed to oxygen ash followed by dilute HF etch todetermine damaged thickness.

Film dielectric constant is shown in Table 7 while O₂ ash damagedthickness are shown in Table 8.

TABLE 7 Dielectric constant of carbon doped silicon oxide film by H₂/Arplasma treatment. Dielectric constant after H₂/Ar plasma treatment(before O₂ ash) H₂/Ar plasma treatment only 3.6 200° C. anneal beforeH₂/Ar 2.8 plasma treatment 300° C. anneal before H₂/Ar 2.8 plasmatreatment 400° C. anneal before H₂/Ar 3.2 plasma treatment

TABLE 8 Damaged thickness of carbon doped silicon oxide film afterexposed to O₂ ash. Damaged thickness after O₂ ash (Å) H₂/Ar plasmatreatment only 30 200° C. anneal before H₂/Ar 32 plasma treatment 300°C. anneal before H₂/Ar 27 plasma treatment 400° C. anneal before H₂/Ar31 plasma treatment

Additional annealing prior to H₂/Ar plasma treatment shows lowerdielectric constant (k=2.8-3.2) over sample only treated with H₂/Arplasma (k=3.6). The film has oxygen ash damaged thickness of 27-32 Å.

Example 6. Carbon Doped Silicon Oxide Film Using1,1,3,3-tetrachloro-1,3-disilacyclobutane and Ammonia at 300° C.Followed by High Temperature Annealing

Carbon doped silicon oxide film was deposited using1,1,3,3-tetrachloro-1,3-disilacyclobutane as the silicon precursor andammonia at 300° C. in ALD mode using 300 mm commercial cross flowreactor. The ALD steps 2 to 8, shown in Table 9, are repeated to getdesired thickness.

TABLE 9 ALD steps of carbon doped silicon oxide film deposition StepsDescriptions Time Notes 1 Insert Si substrates into a reactor 2 Heatsubstrates to 30 T = 300° C. desired temperature minutes 3 Flow thesilicon  1 Vapor draw; vapor pressure precursor seconds is 14-18 TorrInner chamber (s) Ar = 300 sccm, 8 Torr; Outer chamber Ar = 500 sccm,7.5 Torr 4 Soak Si precursor  3 s Ar gas and precursor flow is stopped.Throttle valve close while maintaining chambers pressure. 5 Flow Ar topurge 10 s Inner chamber Ar = 300 precursor sccm, 8 Torr; Outer chamberAr = 500 sccm, 7.5 Torr 6 Flow NH₃ 25 s NH₃ = 100 sccm Inner chamber Ar= 300 sccm, 8 Torr; Outer chamber Ar = 500 sccm, 7.5 Torr 7 Flow Ar topurge 10 s Inner chamber Ar = 300 precursor sccm, 8 Torr; Outer chamberAr = 500 sccm, 7.5 Torr 8 Remove Si sample from the reactor

The as-deposited sample was left in ambient convert into carbon dopedsilicon oxide film. The growth per cycle (GPC) of the films are 0.45Å/cycle.

The carbon doped silicon oxide film was further treated at 300° C. undernitrogen atmosphere for 1 hour followed by hydrogen-containing plasmatreatment (either H₂ only plasma or H₂/Ar plasma) as describedpreviously.

After plasma treatment, the film was exposed to O₂ ash followed bydilute HF to determine damaged thickness. The dielectric constant anddamaged thickness after O₂ ash are shown in Table 10.

TABLE 10 Dielectric constant of carbon doped silicon oxide film anddamaged thickness after O₂ ash Before After plasma After O₂ ash O₂ ashtreatment (before O₂ ash) and dHF etch damaged dielectric dielectricdielectric thickness Treatment constant (k) constant (k) constant (k)(Å) H₂ only plasma 5.7 3.5 3.5 33 Å H₂/Ar plasma 5.7 2.8 3.2 31 Å

The process demonstrated carbon doped silicon oxide film with highoxygen resistance and low-k before and after oxygen ash process. Highoxygen resistance indicates by low damage thickness as well as low kafter oxygen ash (k<4.0) Example 7. Step Coverage of Silicon ContainingFilm after Plasma Treatment

Carbon doped silicon oxide film was deposited using1,1,3,3-tetrachloro-1,3-disilacyclobutane and ammonia at 300° C. in ALDmode using 300 mm commercial cross flow reactor followed by H₂/Ar plasmaas described in Example 6. The substrate used was patterned wafer withaspect ratio of 1:9 and opening of 180 nm.

Transmission Electron Microscope (TEM) was used to determine surfacecoverage. Table 11 shows film thickness at various locations in thestructure.

TABLE 11 Thickness of carbon doped silicon oxide deposited from 1,1,3,3-tetrachloro-1,3-disilacyclobutane followed by H₂/Ar plasma treatment Top¼ from top Middle ¾ from top Bottom 355 Å 353 Å 360 Å 362 Å 345 Å

Film step coverage is >97%.

Example 8. Chemical Treatment of Carbon Containing Film Deposited from1,1,3,3-tetrachloro-1,3-disilacyclobutane and Ammonia

The carbon doped silicon oxide film deposited from1,1,3,3-tetrachloro-1,3-disilacyclobutane and ammonia at 300° C. asdescribed in Table 9 was annealed at 300° C. in inert for 1 hourfollowed by exposure to chemical treatment usingdiethylaminotrimethylsilane. The chemical treatment parameters are:

T=300° C.; Time=5 min and 25 min; Chamber Pressure=1 Torr

As control, the film was annealed only at 300° C. without any chemicalexposure.

After treatment, film dielectric constant is measured and shown in Table12.

TABLE 12 Film dielectric constant after diethylaminotrimethylsilanetreatment Temperature (° C.) Time (minutes) Dielectric constant (k) Nochemical treatment, 25 5.5 anneal only at 300° C. 300  5 2.9 300 25 2.7

The chemical treatment shows improvement in film dielectric constant,from 5.5 to less than 3.0.

Example 9. Deposition of Carbon Containing Silicon Film Using1,1,3,3-tetrachlorodsilacyclobutane in Octane and Ammonia

A solution of 20 wt. % of 1,1,3,3-tetrachloro-1,3-disilacyclobutane inoctane was used for film deposition. The chemical was delivered usingdirect liquid injection (canister temperature=60° C., Ar flow throughthe vaporizer was 100 sccm. Liquid flow rate was ˜200 mg/min). Vaporizertemperature was 70° C.

The deposition process comprised of the following steps:

TABLE 13 Steps used to deposit silicon containing film using1,1,3,3-tetrachloro- 1,3-disilacyclobutane solution Steps DescriptionsTime Notes 1 Insert Si substrates into a reactor 2 Heat substrates to 5T = 300° C. desired temperature minutes 3 Flow 1,1,3,3-tetrachloro- 2 ChP = 8~10 Torr 1,3-disilacyclobutane seconds 20% in octane 4 Soak Siprecursor 5 s Ar gas and precursor flow were stopped. Throttle valveclosed while maintaining chambers pressure. 5 Flow Ar to purge 10 sprecursor 6 Flow NH₃ 15 s NH₃ = 500 sccm, Chamber pressure = 15 Torr 7Soak NH₃ 20 s NH₃ flow stopped. Throttle valve closed 8 Flow Ar to purgeNH₃ 10 s 9 Flow H₂O vapor 1 hour 300° C., chamber pressure =~30 Torr 10Remove Si substrate from the reactor

Steps 3 to 4 were repeated 5 times before moving to step 5, and steps 3to 8 were repeated multiple times to get desired thickness. Filmcomposition analyzed by XPS are

Si=35.7%; O=36.5%; C=23.0%; N=4.5%; Cl=0.3%.

The deposited film was further annealed in inert environment at 300° C.for 1 hour followed by H₂/Ar plasma treatment.

Treated films were exposed to standard O₂ ash and dipped into dilute HFto determine damaged thickness. The damaged thickness after O₂ ash are38 Å and 37 Å for film treated with H₂ only plasma and H₂/Ar plasmaconsecutively.

Example 10. High Carbon Content Si Oxide Film from In-Situ Processing

A solution of 20 wt. % of 1,1,3,3-tetrachloro-1,3-disilacyclobutane inoctane was used for film deposition. The chemical was delivered usingdirect liquid injection (canister temperature=60° C., Ar flow throughthe vaporizer was 100 sccm. Liquid flow rate was ˜200 mg/min). Vaporizertemperature was 70° C.

The deposition process comprised of the following steps:

TABLE 14 Steps used to deposit silicon containing film using 1,1,3,3-tetrachloro-1,3-disilacyclobutane solution Steps Descriptions Time Notes1 Insert Si substrates into a reactor 2 Heat substrates to 5 T = 300° C.desired minutes temperature 3 Flow 1,1,3,3- 0.5 Chamber pressure = 5Torr tetrachloro- second Precursor temperature = 70° C., 1,3- Ar carriergas = 25 sccm disilacyclobutane Nitrogen for pressure control = andpyridine, 200 sccm co-injection Ar for pressure control = 50 sccm 4 Flowinert gas to 15 s Nitrogen = 200 sccm purge unreacted Ar = 50 sccmprecursors 5 Flow H₂O and 3 s Chamber pressure = 5 Torr pyridine, Waterpressure = 17 Torr co-injection Nitrogen for pressure control = 200 sccmAr for pressure control = 50 sccm 6 Flow inert gas 15 s Nitrogen = 200sccm for purging Argon = 50 sccm 7 Flow H₂O vapor 1 hour 300° C.,chamber pressure =~30 Torr 8 Flow N₂ for 30 min 300-500° C., chamberdrying pressure = 5 Torr 9 Turn on H₂ only 5 min H₂ = 200 sccm; Freq =13.56 plasma MHz, chamber pressure = 2 Torr; power = 100 W 10 Remove Sifilm from the reactor

Steps 3 to 4 were repeated 5 times before moving to step 5, and steps 3to 6 were repeated multiple times to get desired thickness. Step 8, 9,and 10 are optional for comparison.

TABLE 15 Film properties of carbon doped silicon oxide film processedin-situ using 1,1,3,3-tetrachloro-1,3-disilacyclobutane. WER Density SiO C N Cl (Å/s) (g/cc) at. % at. % at. % at. % at. % No 0.08 1.34 36.0433.17 28.69 0.6 1.5 additional process N₂ dry <0.02 1.44 36.19 34.3727.33 0.3 1.8 N₂ dry + <0.02 1.58 36.39 35.43 25.68 0.54 1.9 H₂ plasma

The resulting film has film properties in Table 15. Film etch rates arevery low, i.e. 0.12× thermal oxide, for as-deposited film with noanneal. The etch rates dropped to level below our detection limit afteradditional processing (N₂ dry or N₂ dry and plasma).

Film density for as-deposited film is 1.34 g/cc with slightdensification with additional N2 dry or N₂ dry and H₂ plasma treatment.In all cases, the film has high carbon content 25-29% and low Cl content(<2%).

Example 11. Low Dielectric Constant Carbon Doped Silicon Oxide FilmDeposited from 1,1,3,3-Tetrachloro-1,3-Disilacyclobutane andWater/Pyridine

1,1,3,3-tetrachloro-1,3-disilacyclobutane and H₂O were used for filmdeposition. Pyridine was used as a reaction catalyst. The chemical(canister temp=70° C.) was delivered with Ar sweeping through theprecursor canister. Water temperature was 17° C. (vapor pressure=15torr) and water vapor was delivered with vapor draw, and pyridine tempwas 25˜35° C. (vapor pressure=15˜25 torr) and pyridine vapor wasdelivered with vapor draw. Main N₂ flow rate was 200 sccm, and Ar flowrate was 50 sccm.

The deposition process comprised of the steps described in Table 16.

TABLE 16 Deposition steps used in depositing Si-containing film from1,1,3,3- tetrachloro-1,3-disilacyclobutane and water/pyridine. StepsDescriptions Time Notes 1 Insert Si substrates into a reactor 2 Heatsubstrates 5 T = 40° C. to desired minutes temperature 3 Flow 1,1,3,3-0.5 Chamber pressure = 5 Torr tetrachloro- second Precursor temperature= 70° C., 1,3- Ar carrier gas = 25 sccm disilacyclobutane Nitrogen forpressure control = and pyridine, 200 sccm co-injection Ar for pressurecontrol = 50 sccm 4 Flow inert gas to 15 s Nitrogen = 200 sccm purgeunreacted Ar = 50 sccm precursors 5 Flow H₂O and 3 s Chamber pressure =5 Torr pyridine, Water pressure =17 Torr co-injection Nitrogen forpressure control = 200 sccm Ar for pressure control = 50 sccm 6 Flowinert gas 15 s Nitrogen = 200 sccm for purging Argon = 50 sccm 7 RemoveSi substrate from the reactor

Steps 3 to 6 were repeated 500 times to get desired thickness.

The film as-deposited has refractive index of 1.53 and GPO of 0.8Å/cycle. The film composition, measured by XPS, is: Si=35.3%, 0=34.0%,C=28.9%, N=0.6% and Cl=1.3%. Film density is 1.8 g/cc and dilute etchrate is 0.08 Å/s.

The film then subjected to standard ex-situ H₂/Ar plasma treatment at300° C. as described previously. The film dielectric constant wasmeasured before and after plasma treatment is 3.6, which is improvedfrom as-deposited film (k=6.1)

Example 12. High Carbon Content Si Oxide Film from In-Situ Processing

A solution of 20 wt. % of 1,1,3,3-tetrachloro-1,3-disilacyclobutane inoctane was used for film deposition. The chemical was delivered usingdirect liquid injection (canister temperature=60° C., Ar flow throughthe vaporizer was 100 sccm. Liquid flow rate was 200 mg/min). Vaporizertemperature was 70° C.

The deposition process comprised of the steps described in Table 17.

TABLE 17 Deposition steps used in depositing silicon containing filmusing 1,1,3,3- tetrachloro-1,3-disilacyclobutane solution StepsDescriptions Time Notes 1 Insert Si substrates into a reactor 2 Heatsubstrates to 5 T = 300° C. desired temperature minutes 3 Flow1,1,3,3-tetrachloro- 2 Ch P = 8 Torr 1,3-disilacyclobutane seconds 20%in octane 4 Soak Si precursor 5 s Ar gas and precursor flow werestopped. Throttle valve closed while maintaining chambers pressure. 5Flow Ar to purge 10 s precursor 6 Flow NH₃ 15 s NH₃ = 500 sccm, Chamberpressure = 15 Torr 7 Soak NH₃ 20 s NH₃ flow stopped. Throttle valveclosed 8 Flow Ar to purge NH₃ 10 s 9 Flow H₂O vapor to 1 hour 300° C.,chamber pressure = convert to SiO₂ 5 Torr 10 Remove Si film from thereactor

Steps 3 to 4 were repeated 5 times before moving to step 5, and steps 3to 8 were repeated multiple times to get desired thickness. The Step 9is optional for some wafers in order to get comparison between H₂Oin-situ anneal and conversion in ambient.

Table 18 shows similar film composition as measured by XPS, for bothcarbon doped silicon oxide converted in ambient and the one with in-situH₂O treatment.

TABLE 18 Comparison of Film Composition of Carbon Doped Silicon Oxide SiO C N Cl Ambient 34.69 41.4 21.82 1.74 0.35 conversion In-situ H₂O 35.238.22 23.49 2.82 0.27

Example 13. High Temperature Annealing of Carbon Doped Silicon OxideFilm

Carbon doped silicon oxide film was deposited using1,1,3,3-tetrachloro-1,3-disilacyclobutane and ammonia at 300° C. in ALDmode using 300 mm commercial cross flow reactor. The ALD steps, shown inTable 8, are repeated to get desired thickness.

The as-deposited carbon doped silicon oxide film was annealed at 500° C.to 800° C. in inert for 1 hour.

The film dielectric constant shows in Table 19.

TABLE 19 Dielectric constant of Si-containing film, deposited using1,1,3,3-tetrachloro-1,3- disilacyclobutane and ammonia, after thermalannealing dielectric 5 Annealing constant (k) after temperatureannealing (before (° C.) oxygen ash) No anneal (room 5.7 temperature)500° C. 2.6 600° C. 2.3 700° C. 2.6 800° C. 3.9

High temperature annealing is effective in reducing film dielectricconstant.

Comparative Example 1: Effect of Hydrogen Plasma Treatment and OxygenAshing on Carbon Doped Silicon Oxide Film Deposited by PECVD UsingDiethoxymethysilane

Carbon doped silicon oxide film was deposited using diethoxymethylsilane(DEMS) using a 200 mm commercial PECVD tool at 300° C. The processparameters are as follow: Power=500 W; Pressure=9 Torr; Si precursorflow=500 sccm; He flow=300 sccm; film thickness=500 Å.

The as-deposited film has composition shown in Table 20

TABLE 20 Film composition of Carbon doped silicon oxide film using DEMSPECVD process, measured by XPS Measurement depth (Å) C % N O Si Cl 021.8% ND 44.8% 27.0% ND 100 28.3% ND 46.4% 32.7% ND

The film density is 1.48 g/cc. WER in dilute HF (1:99 49% HF and DIwater) for as-deposited (before H₂ plasma) is in Table 21. The filmshows very high dilute HF etch resistance, indicating by low etch rate.

TABLE 21 WER in dilute HF (1:99, 0.5 wt. %) for Carbon doped siliconoxide from as-deposited PECVD DEMS (before H₂ plasma). The thermalsilicon oxide reference etch rate is 0.48 ± 0.02 Å/s Etch time Carbondoped silicon oxide (seconds) film Thickness (Å) Etch rate (Å/s) 0 515N/A 15 513 0.16 195 512 0.03

The film was then treated with H₂ plasma for 5 minutes at 300 W and 300°C. After H₂ plasma treatment, the sample was exposed to oxygen ashing.Both hydrogen plasma treatment and oxygen ashing processes are the sameas described previously.

Table 22 shows dielectric constant measurement of PECVD DEMS samples

TABLE 22 PECVD DEMS dielectric constant after H₂ plasma treatment and H₂plasma followed by oxygen ashing Dielectric Before 5 min After 5 min H₂constant H₂ H₂ plasma and (k) plasma plasma oxygen ashing PECVD DEMS 3.23.7 5.5

The dielectric constant increases after H₂ plasma from 3.2 to 3.7indicating higher damaged thickness. Oxygen ashing further increasesfilm dielectric constant to 5.5. The dilute HF (1:99 49% HF and DIwater) characterization after H₂ plasma followed by oxygen ashing,tabulated in Table 17.

TABLE 23 WER in dilute HF (1:99) for carbon doped silicon oxide fromPECVD DEMS after H₂ plasma followed by oxygen ashing ash. The thermalsilicon oxide reference etch rate is 0.48 ± 0.02 Å/s Etch time Carbondoped silicon oxide (seconds) film Thickness (Å) Etch rate (Å/s) 0 484N/A 15 435 3.29 195 377 0.32

The Carbon doped silicon oxide film clearly shows damaged layerthickness more than 100 Å. Film etch rate for film after oxygen ash ismuch higher than (>10×) as deposited film. High film dielectric constantafter exposing to oxygen ashing process is consistent with thick damagedlayer from oxygen ash.

Comparative Example 2. Silicon Containing Film Control without PostDeposition Treatment

Carbon doped silicon oxide film was deposited using thermal ALD processusing 1,1,3,3-tetrachloro-1,3-disilacyclobutane and ammonia at 300° C.as described in Table 3. After deposition the film was then anneal atroom temperature in air for 3 hours at 300° C. Standard oxygen ash wasperformed on the carbon doped silicon oxide film. Dilute HF was used todetermine damaged thickness, shown in Table 24.

TABLE 24 Dilute HF etch rate of carbon doped silicon oxide film afterexposed to oxygen ash Etch time Carbon doped silicon oxide (seconds)film Thickness (Å) Etch rate (Å/s) 0 626 — 15 586 2.67 30 533 3.56 60413 3.99 120 364 0.81 240 350 0.12 480 343 0.06

The etch rate of the first ˜260 Å from the surface shows very high etchrate compared to as deposited film (0.01 Å/s) suggest that carbon isremoved. Carbon removal is consistent with damaged film from oxygen ash.

Example 10. Formulation of 1,1,3,3-tetrachloro-1,3-disilacyclobutane

Table 25 summarizes the solubility of1,1,3,3-tetrachloro-1,3-disilacyclobutane in various solvents aspotential formulation for delivery of vapors via direct liquid injectionsince 1,1,3,3-tetrachloro-1,3-disilacyclobutane is a solid at roomtemperature.

Solubility mol % (moles of 280/total Solvent wt. % moles) OMCTS 23.020.6 dodecane 26.2 18.3 HMDSO 30.5 24.0 octane 47.3 31.2 cyclooctane51.2 34.2 toluene 57.7 35.7

While the invention has been described with reference to certainembodiments, it will be understood by those skilled in the art thatvarious changes may be made and equivalents may be substituted forelements thereof without departing from the scope of the invention. Inaddition, many modifications may be made to adapt a particular situationor material to the teachings of the invention without departing from theessential scope thereof. Therefore, it is intended that the inventionnot be limited to the particular embodiment disclosed as the best modecontemplated for carrying out this invention, but that the inventionwill include all embodiments falling within the scope of the appendedclaims.

1. A method for forming a carbon doped silicon oxide film having carboncontent ranging from 15 at. % to 30 at. % via a thermal ALD process, themethod comprising: a) placing one or more substrates comprising asurface feature into a reactor; b) heating to reactor to one or moretemperatures ranging from ambient temperature to about 550° C. andoptionally maintaining the reactor at a pressure of 100 torr or less; c)introducing into the reactor at least one silicon precursor having twoSi—C—Si linkages selected from the group consisting of1-chloro-1,3-disilacyclobutane, 1-bromo-1,3-disilacyclobutane,1,3-dichloro-1,3-1,3-disilacyclobutane,1,3-dibromo-1,3-disilacyclobutane,1,1,3-trichloro-1,3-disilacyclobutane,1,1,3-tribromo-1,3-disilacyclobutane,1,1,3,3-tetrachloro-1,3-disilacyclobutane,1,1,3,3-tetrabromo-1,3-disilacyclobutane,1,3-dichloro-1,3-dimethyl-1,3-disilacyclobutane,1,3-bromo-1,3-dimethyl-1,3-disilacyclobutane,1,1,1,3,3,5,5,5-octachloro-1,3,5-trisilapentane,1,1,3,3,5,5-hexachloro-1,5-dimethyl-1,3,5-trisilapentane,1,1,1,5,5,5-hexachloro-3,3-dimethyl-1,3,5-trisilapentane,1,1,3,5,5-pentachloro-1,3,5-trimethyl-1,3,5-trisilapentane,1,1,1,5,5,5-hexachloro-1,3,5-trisilapentane,1,1,5,5-tetraachloro-1,3,5-trisilapentane; d) purging with an inert gas;e) providing a nitrogen source into the reactor to react with thesurface to form a carbon doped silicon nitride film; f) purging withinert gas to remove reaction by-products; g) repeating steps c to f toprovide a desired thickness of a resulting carbon doped silicon nitride;h) treating the resulting carbon doped silicon nitride film with anoxygen source at one or more temperatures ranging from about ambienttemperature to 1000° C. to convert the carbon doped silicon nitride filminto a carbon doped silicon oxide film; and i) providing post-depositionexposing the carbon doped silicon oxide film to a plasma comprisinghydrogen.
 2. A film formed according to the method of claim 1 having adielectric constant of less than about 4, and a carbon content of atleast about 10 at. %.
 3. A film formed according to the method of claim1 having an etch rate of at least 0.5 times less than thermal siliconoxide, wherein the etch rate is measured with diluted HF.
 4. A filmformed according to the method of claim 1 having an etch rate of atleast 0.1 times less than thermal silicon oxide, wherein the etch rateis measured with diluted HF.
 5. A film formed according to the method ofclaim 1 having an etch rate of at least 0.05 times less than thermalsilicon oxide, wherein the etch rate is measured with diluted HF.
 6. Afilm formed according to the method of claim 1 having an etch rate of atleast 0.01 times less than thermal silicon oxide, wherein the etch rateis measured with diluted HF.
 7. A film formed according to the method ofclaim 1 having a damage layer of 50 Å or less following an oxygen ashingprocess.
 8. A film formed according to the method of claim 1 having adamage layer of 20 Å or less following an oxygen ashing process.
 9. Afilm formed according to the method of claim 1 having a damage layer of10 Å or less following an oxygen ashing process.
 10. A film formedaccording to the method of claim 1 having a damage layer of 5 Å or lessfollowing an oxygen ashing process.
 11. The method according to claim 1wherein the step h) of treating the resulting carbon doped siliconnitride film with an oxygen source is performed at one or moretemperatures ranging from or from about 100° C. to 400° C.
 12. A methodfor forming a carbon doped silicon oxide film having carbon contentranging from 15 at % to 30 at. % via a thermal ALD process, the methodcomprising the method comprising: a. placing one or more substratescomprising a surface feature into a reactor; b. heating the reactor toone or more temperatures ranging from ambient temperature to about 150°C. and optionally maintaining the reactor at a pressure of 100 torr orless; c. introducing into the reactor at least precursor having twoSi—C—Si linkages selected from the group consisting of1-chloro-1,3-disilacyclobutane, 1-bromo-1,3-disilacyclobutane,1,3-dichloro-1,3-1,3-disilacyclobutane,1,3-dibromo-1,3-disilacyclobutane,1,1,3-trichloro-1,3-disilacyclobutane,1,1,3-tribromo-1,3-disilacyclobutane,1,1,3,3-tetrachloro-1,3-disilacyclobutane,1,1,3,3-tetrabromo-1,3-disilacyclobutane,1,3-dichloro-1,3-dimethyl-1,3-disilacyclobutane,1,3-bromo-1,3-dimethyl-1,3-disilacyclobutane,1,1,1,3,3,5,5,5-octachloro-1,3,5-trisilapentane,1,1,1,3,3,5,5,5-octachloro-1,3,5-trisilapentane,1,1,1,3,3,5,5,5-octachloro-1,5-dimethyl-1,3,5-trisilapentane,1,1,1,5,5,5-hexachloro-3,3-dimethyl-1,3,5-trisilapentane,1,1,3,5,5,5-pentachloro-1,3,5-trimethyl-1,3,5-trisilapentane,1,1,1,5,5,5-hexachloro-1,3,5-trisilapentane,1,1,5,5-tetraachloro-1,3,5-trisilapentane and a catalyst; d. purgingwith an inert gas e. providing vapors of water into the reactor to reactwith the precursor as well as a catalyst to form a carbon doped siliconoxide as-deposited film; and f. purging with inert gas to removereaction by-products; wherein steps c to f are repeated to provide adesired thickness of carbon doped silicon oxide.
 13. The method of claim12 further comprising post-deposition treatment of the carbon dopedsilicon oxide film with a thermal anneal at temperatures from 300 to700° C.
 14. The method of claim 12 further comprising hydrogen plasmatreatment of the carbon doped silicon oxide film with a plasmacomprising hydrogen.